A pressure switch typically includes a separate switch, such as a microswitch, and a pressure responsive section for actuating the switch. A pressure switch has a differential which enables it to close the switch in response to one pressure level and to open the switch in response to a different pressure level. Pressure switches of this kind are shown, for example, in my prior U.S. Pat. Nos. 3,651,292, 3,711,222 and 4,081,621.
Pressure switches of the kind described and claimed in my prior patents work very satisfactorily. However, each of these pressure switches employs a separate microswitch as the switching element. Unfortunately, microswitches have become increasingly expensive, and so it is desirable to eliminate the separate microswitch as a component of the pressure switch.